Mitsubishi Q173DCPU Motion CPU Module

The Mitsubishi Q173DCPU is a high-performance motion CPU module for the MELSEC Q Series programmable logic controller platform. Designed for advanced motion control applications, this dedicated motion controller can control up to 32 axes with high-speed, high-precision positioning. The Q173DCPU utilizes SSCNET III (Servo System Controller Network) to connect to Mitsubishi servo amplifiers, providing real-time, synchronized control of multiple axes. It is suitable for demanding applications including CNC machines, robotic systems, packaging equipment, and semiconductor manufacturing tools.

Technical Specifications

The Q173DCPU uses a dedicated high-performance CPU for motion control processing separate from the PLC CPU in a multi-CPU configuration. Number of control axes: maximum 32 axes (with single module). When three Q173DCPU modules are used together, up to 96 axes can be controlled. Operating period (default): SV13 mode: 0.44 ms for 1 to 6 axes, 0.88 ms for 7 to 18 axes, 1.77 ms for 19 to 32 axes. SV22 mode: 0.44 ms for 1 to 4 axes, 0.88 ms for 5 to 12 axes, 1.77 ms for 13 to 28 axes, 3.55 ms for 29 to 32 axes. Servo amplifier connection: SSCNET III (two systems). Peripheral device interface: via sequencer CPU (USB/RS-232). The module supports manual pulse generator operation function with up to 3 manual pulse generators. Synchronous encoder operation function: up to 12 synchronous encoder units can be used (when SV22 mode is used). Manageable units: Q172DLX (max 4 units/CPU), Q172DEX (max 6 units/CPU), Q173DPX (max 4 units/CPU). I/O capacity: 4096 I/O points maximum. Program capacity: 16K steps. Basic processing speed: 1.9 ns (for LD instruction). Current consumption: 1.25 A (5 V DC). Dimensions: 98 mm (H) × 27.4 mm (W) × 119.3 mm (D). Weight: 0.33 kg.

Key Features

• Motion control of up to 32 axes (single module) or 96 axes (three modules)

• SSCNET III (Servo System Controller Network) for high-speed servo communication

• Multi-CPU system support (works alongside Q series PLC CPU)

• Linear interpolation (2 to 4 axes), circular interpolation (2 axes), helical interpolation

• High-speed operation: 0.44 ms for 1-6 axes (SV13), 0.44 ms for 1-4 axes (SV22)

• SV13, SV22, and SV43 motion control firmware support

• Manual pulse generator operation (3 generators)

• Synchronous encoder operation (12 units)

• Advanced positioning functions: electronic cam, electronic gear, superimposed control

• Teaching function and program less operation

Motion Control Capabilities

The Q173DCPU provides a comprehensive suite of motion control functions. Interpolation capabilities include linear interpolation (2 to 4 axes), circular interpolation (2 axes), and helical interpolation (3 axes). Positioning control methods include point-to-point (PTP) positioning, path control, speed control, and torque control. Advanced functions include electronic cam operation for synchronizing axes to a master axis, electronic gear for variable ratio speed control, superimposed control for adding motion offsets, and acceleration/deceleration control (S-curve, trapezoidal). The module supports absolute and incremental positioning systems, with positioning data stored in the motion CPU's buffer memory. Up to 3200 positioning points are available (SV13/SV22 mode), and approximately 10600 positioning points are available with SV43 mode. The module also supports high-speed oscillation reduction control.

Multi-CPU System Integration

The Q173DCPU operates in a multi-CPU configuration alongside a standard Q series PLC CPU (e.g., Q00UJ, Q03UD). The motion CPU handles positioning calculations and servo control while the PLC CPU manages I/O, HMI communication, and sequential logic. The two CPUs communicate via high-speed shared memory, enabling synchronized data exchange. The multi-CPU system can contain up to 4 CPU modules (including PLC CPU, motion CPU, and other specialty CPUs). The motion CPU uses dedicated motion SFC (Sequential Function Chart) programming for sequence control of motion operations. The system is configured using Mitsubishi GX Works2 and Motion SFC programming software.

Applications

The Q173DCPU is suitable for high-speed and high-precision motion control applications including: CNC machine tools (milling, turning, grinding), industrial robots (SCARA, delta, articulated), high-speed pick-and-place systems, packaging machinery (filling, capping, labeling), semiconductor manufacturing (wafer handling, die bonding), printing and converting equipment, and electronic assembly systems. The SSCNET III network supports up to 400 m between nodes, allowing distributed servo systems in large machinery.

Installation and Configuration

The Q173DCPU mounts in a dedicated slot of a Q series multi-CPU base unit (e.g., Q38DB, Q312DB). The module must be installed to the left of the PLC CPU in the multi-CPU configuration. SSCNET III communication uses optical fiber cables (available from Mitsubishi) between the motion CPU and servo amplifiers. Set the network parameters (station numbers, axis assignments) using GX Works2 software. The motion SFC program is created separately and downloaded via the PLC CPU's programming port. Parameter settings include operation patterns, electronic gear ratios, acceleration/deceleration curves, and limit switch assignments. The module supports a maximum cable length of 0.45 meters within the rack.

Diagnostics and Maintenance

The Q173DCPU features LED indicators on the front panel: RUN (green), ERR (red), and communication status LEDs for each SSCNET III channel. Error codes can be read via GX Works2 or using the motion CPU's error history buffer. The module provides real-time monitoring of axis status, servo amplifier alarms, and network communication errors. The SSCNET III system automatically detects cable breaks and reports the location. Lithium battery backup (sold separately) retains motion program and parameters during power loss. Regular maintenance includes checking optical fiber connections and verifying battery voltage.

Environmental and Compliance

The Q173DCPU is CE and RoHS compliant. Operating temperature: 0°C to 55°C. Storage temperature: -20°C to 70°C. Humidity: 10-90% non-condensing. The module is rated IP20 and must be installed in a control cabinet. Vibration resistance: 2g (10-55 Hz).

Conclusion

The Mitsubishi Q173DCPU motion CPU module provides powerful, high-speed motion control for the Q Series platform. Its 32-axis capability, SSCNET III real-time control, and integration with PLC CPUs make it a suitable choice for demanding multi-axis automation applications requiring coordinated motion and precise positioning.